Method of producing halogen-oxygen compounds by electrolysis.



sira rns harass IEATHIAS PIER, OF SCI-ILACHTENSEE, NEAR BER-LIN, GERMANY, ASSIGNOR TO E. I. DU

FONT DE NEIVIOURS POW'IDER COMPANY, OF WILMINGTON, DELA'WARE, A GOR-IPORA-' TION OF NEW JERSEY.-

METHOD OF PRODUCING HALOGEN-OXYGEN COMPOUNDS BY ELEGTROLYSIS.

sas es.

Specification of Letters Patent.

Patented July as, ten.

' Application filed April 29, 1911. Serial Il'o. 624,136.

T all whom it may concern:

Be it known that I, Marinas PIER, a subeet of the Emperor of Germany, residing at Schlachtensee, near Berlin, Germany,-

have invented a new and useful Improvement. in Methods of Producing 'Halogen- Oxygen Compounds by Electrolysis, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of this specification.

It is known that high yields of halogen oxygen compounds have been obtained by electrolysis by using precautions to prevent the reaction of the hypo-halogen compounds .at the cathode and thus the prevention of the formation of oxygen at the anode.- It is also known that the reduction of the halogen compounds at the cathode is, to a great erg-- tent, prevented by means of the addition of certain materials for instance, chromate, to the electrolyte. The formation of oxygen is partly due to the fact that the temperature is too high, and partly to the fact that the electrolyte, in most instances, does not react with neutral or very weak acid. No matter how the operation may be carried out, the maintenance of. the electrolyte in this condition is always efiected with great difficulties, due to the fact. that in neutral, or in weak acid solution, chlorin escapes, until the solution reacts alkaline. It has been attempted to overcome this difliculty by pass ing a current of chlorin into or over the electrolyte, or from time to time adding hydrochloric acid. ,Both of these methods have the objection that the hypohalogen compounds are suddenly decomposed, evolving chlorin, and the reaction soon sets in again.

overcome these difliculties and also maintain the electrolyte at a constant level by adding to the neutral electrolyte a liquid which is not miscible with the electrolyte but which readily dissolves chlorin. This liquid should be previously saturated with chlorin. The gases developed, particularly chlorin, are brought into intimate contactwith this liquid in such a manner that the gas does again to the electrolyte. -The liquid or material used should be one which will absorb- Further, constant watching is'required. I

not escape and isebsorbed and returnedused and is especially suited for this purpose, but other liquids or solids which ab- ,sor'b chlorin may be added to electrolyte. it thqoperation is carried on at a temperature which will or may volatilize the added lid uid, a reflux condenser should be used.

In practice I have used the following electrolyte or bath: neutral sodium chlorid sclution diluted with 0.2% of chrom'ate and 20 to 30 vol. per cent. of tetra chlorid of can bon. The anode is formed of platimiun-iridium and the cathode of graphite, all in a closed cell. With this I have obtained practically the theoretical yield of total halogenoxygen compound on current used, the chlorid content being about In the drawing is represented in section an apparatus for carrying out my method;

a is the electrolyzing cell, 7) the anode, c the cathode, d the electrolyziiig solution, 6 is a separate receptacle, having communica tion with the interior of the electrolyzing cell, by means of passage f. v

g are the jacketed walls surrounding the liquid h, tetra chlorid of carbon, in the receptacle e for cooling the liquid.

2' is a pipe communicating with the upper portion of the electrolyzing cell a, and entering the uppe portion of liquid 72. in receptacle e.

j is an outlet drogen gas.

Thehydrogen and chlorin gases which form in the cell c; pass out through the pipe a into the liquid in receptacle e. In this pipe for the passage of hyliquid the chlorin gas is absorbed, and byreason of the diffusion, is led back to the electrolyte through the passage 7.

Having now fully described my invention, what I claim and desire to protect by Letters Patent is:

1'. The improvement in the method of pro ducing halogen-oxygen compounds by electrolysls, which consists in adding to the electrolyte a substance which absorbs and readily releases chlorin gas. I

2. The improvement in the method of producing halogen oxygen compounds by electrolysis, which consists in allowing the evolved chlorin gases to escape from the cell, absorbing the same in a substance whichabsorbs and readily gives up said chlorin gas, and returning the gas to the electrolyte;

producing halogen-oxygen compounds by electrolysis, which consists in addingto the electrolyte a liquid which absorbs and readily releases chlorin gas.

4. The improvement in the method of producing halogen oxygen compounds by elec trolysis, which consists in allowing the evolved chlorin gases to escape from the cell, absorbing the same in a liquid which absorbs and readily gives up said ch'lorin gas, and returning the gas to the electrolyte.

The improvement in the method of producmg halogen-oxygen compounds by elec Jtrolysis, which consists 1n addlng to the electrolyte a liquid which is not miscible with the electrolyte, and which absorbs and readily releases chlorin gas.

6., The .ilTlPl'OYGl'DGIlt in the method of producing halogen oxygen compounds by electrolysis; which consists in allowing the evolved chlorin gases to escapet'rom the cell, absorbing the same in a liquid, which. is not miscible with the electrolyte, and which absorbs and readily gives up said chlorin gas, and returning the gas to the electrolyte.

7. The in'iprovement in the method ofproducing halogen oxygen compounds by electrolysis, which consists in adding to the electrolyte tetra chlorid of carbon.

8. The improvement in the method of prol v i 1 l l ducing halogen oxygen compounds by electrolysis, which consists in allowing the evolved chlorin gases to escape from the cell, absorbing the same in tetra chlorid of carbon, and returning the gas to the electrolyte.

J. The improvement in the method of producing halogen-oxygen compounds, which consists in providing a liquid independent of the electrolyte, and which liquid absorbs and readily gives up chlorin, said liquid being in liquid connection with the lower portion of the electrolyte and in gas connnunication with the upper portion of the electrolyzing cell.

10. The improvement in the method of producing halogen-oxygen compounds,which consists in providing tetra chlorid of carbon independent of the electrolyte, said tetra chlorid of carbon being in liquid connection with the lower portion of the electrolyte and in gas con'lmunication with the upper portion of the electrolyzing cell.

In testimony of which invention, I have hereunto set mv hand, at Berlin, on this (i day of April, 1911.

M ATH I AS PIE It.

Witnesses:

l'VoLonMAR HAUPT, Ilnrvnr HAsrnu. 

